When a shoe company wants to create a video ad from existing images, which ad format should they select?

The slideshow format is the ideal choice for a shoe company looking to create a video ad from existing images. This format allows the user to compile multiple images into a cohesive video presentation, typically with the option to add music and transitions that can enhance the visual storytelling.

Using a slideshow is an effective way to showcase a range of products or different angles and styles of the same product in a dynamic format, capturing viewers' attention more effectively than static images alone. The automatic play and looping features common in slideshows also make it easy for viewers to engage with the content without requiring additional action, which can lead to higher potential engagement rates.

Other formats like video require pre-existing video content or the ability to create a new video, while an image carousel focuses more on static images being swiped through rather than animated transitioning. Collection ads typically blend products in a grid layout that makes for an interactive shopping experience rather than a video ad format. Thus, for the goal of creating a video-like advertisement from images, the slideshow format stands out as the most suitable option.